Photographic developer



Patented Oct. o I

UNITED STATES PA-TENT OFFICE rnorocimrmc nnvnnorsa Harold DQBussell, Rochester, N. Y., asiignor to Eastman Kodak Company, Rochester, N. Y., a

corporation of New York No Drawing. Application August 1,1934, Serial No. 137,958

4 Claims. (01. 95-88) I This invention relates to photographic de- Bath No.2 I velopers, and more particularly to developers in Sodium sumte 10 grams 3 1 3 ifi m replaced a Sodium salt or triethanolamine 50''. do.

5 Alkaline developers have been known and used water to H H e 1 mar 6 for many years. These developers usually con- The film 01' Plate first immersed in Bath N tain developing agents, a so-called preservative, 2 t0 3 minutes n then in Bath N 2 until such as sodium sulfite, and an alkali, such as v pm i mpl sodium or potassium carbonate, or sodium or EXAM-91,33

10 potassium hydroxide. In recent years various p 10 sensitive materials and photographic processes E1011 5 have appeared with which the use of these relanydrpqumone 10 tively strong alkalies is objectionable for one sodium sumte: 75 reason or another. One object of this invention sqdium Salt is to provide developers containing a milder al- Pmassmm bromide 5 9- 15 kali. Another. object is to provide developers Piltassium' Mme which will givesatisfactory results without the water r-" 1 liter objectionable features of those containing the 1 LE 4 alkalies previously used, such as the formation El I 5 of gas blisters when a film developed in a deum 10 s 20 veloper containing carbonate is immersed in an Hy one ""7 fixing th 4 I have discovered by using a Sodium Of triethah0 1amine go. of triethanolamine as the alkaline component, 5:22:33 :Jggg '7 o 01 g-v 2- I a a ggg' g e a be p ed w h ulfi all these, water to make 1 um The odi m slalts f h lam may be The above exampies'show the sodium salt of I P p y; dissolving powdered Sodium triethanolamine as the sole alkaline component droxide in triethanolamine, with heating. The of the developer. I have found. however, that amount of sodium hydroxide used is one, two or mixtures of di salt of trie'thanolamine 30 three eqmvalent Weights, depending upon Wham with other alkalies are advantageous for some er the mono-, dior tri-sodium salt of triethapurposes, r example, I ma'y'use a'mixture of nolamine is desired. The three salts, or mixtures caustic soda, bo x, -1 a, sodium salt of, tr ither f. m y be d interchangeflbly in (level-1 ethanolamine. Or I may us'e a mixture of sodmrmulseium metaborate' and a sodium salt of triethanol- 35 suitable developer formula! embodying 5 1 amine. Following is an example of a developer vention are given here, by way of example. in which such a mu at alkaues is used EXAMPLE 1 EXAMPLE 5 40 40 Hydroquinone 10 grams Elm 2 grams Sodium sulflte 10 do, 5 Potassium bromide; 5 do. Sodium sulfite sodium salt of triethanolamine so do. Sodium metabomte-e e water to make 1 -Sodium salt of triethanolamine 10 do. 45

Potassium bromide 2 do. I mm 2 Water to make 1 liter Two.B FQ'BMU'LA will be understood I am not to be Bath 1 by the above examples except as indicated in the appended claims. 50

Eion 5 grams While I have spoken of the sodium salts oi. Hydroq e 10 do. triethanolamine, it will be apparent that I may Sodium sulflte 100 do. also use the potassium or other alkali metal Sodium bisulfite 5 do. salts of .triethanolamine.

- Water to make 1 liter What .I claim as my invention and desire to 55 be secured by Letters Patent of the United States 3. A photographic developer comprising a deis: veloping agent and an alkali, at least 25%, ap- 1. A photographic developer comprising a deproximately, of the alkali consisting of an alkali veloping agent and, as an essential alkaline-remetal salt of triethanolamine.

5 acting component of the developer, an alkali 4. A photographic developer comprising a de- 5 metal salt. of triethanoiamine. veioping agent and an alkali, at least 25%, ap-

2. A photographic developer comprising a deproximately, of the alkali consisting of a sodium veloping agent and, as an essential alkaline-resalt of triethanolamine. acting. component of the developer, a sodium salt 10 01 triethanolamine. HAROLD D. RUSSELL. 1o 

